A long solenoid carrying current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is :
2B
4B
B/2
B
The magnetic field of a given length of wire carrying a current for a single turn circular coil at centre is B, then its value for two turns for the same wire when same current is flowing on it :
B/4
The magnetic field at a distance r from a long wire carrying current I is 0.4 T. The magnetic field at a distance 2r is
0.2 T
0.8 T
0.1 T
1.6 T
when a charged particle moving with velocity is subjected to a magnetic field of introduction , the force on it is non – zero. This implies that
Angle between is necessarily 90o
Angle between can have any value other than 90o
Angle between can have any value other than zero and 180o
Angle between is either zero or 180o
Tesla is the unit of
magnetic flux
magnetic field
magnetic induction
magnetic moment
Two circular coils 1 and 2 are made from the same wire but the radius of the 1st coil is twice that of the 2nd coil. What is the ratio of potential difference applied across them so that the magnetic field at their centres are same?
3
4
2
6
A 10 eV electron is circulating in a plane at right angles to a uniform field of magnetic induction 10-4 Wb/m2 ( =1.0 gauss). The orbital radius of the electron is
12 cm
16 cm
11 cm
18 cm
Two equal electric currents are flowing perpendicular to each other as shown in the figure. AB and CD are perpendicular to each other and symmetrically placed with respect to the currents, where do we expect the resultant magnetic field to be zero?
On AB
On CD
On both AB and CD
On both OD and BO
At what distance from a long straight wire carrying a current of 12 A will the magnetic field be equal to 3 x 10-5 Wb/m2?
8 × 10-2 m
12 × 10-2 m
18 × 10-2 m
24 × 10-2 m
The magnetic induction at a point P which is at the distance of 4 cm from a long current carrying wire is 10-3 T. The field of induction at a distance 12 cm from the current will be
3.33 × 10-4 T
1.11 × 10-4 T
3 × 10-3 T
9 × 10-3 T
